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Stoneflies - Plecoptera: Perlodidae of Gunnison County, Colorado

Pictetiella expansa - Autumn Springfly

(Banks) 1920
Updated 8 Feb 2017
TSN 103188

Notice the dark stripe at the end of the cerci (tails). That trait identifies our local Pictetiella nymphs in the field or lab. This animal was caught and released in Copper Creek, July 2012. :-)

On this website:
Key to Perlodidae Nymphs

Other Websites:


Banks,N 1920 New neuropteroid insects. Bulletin of the Museum of Comparative Zoology at Harvard College 64: 297-362.
     Described as Perla expansa.

Baumann,RW 1973 Studies on Utah stoneflies (Plecoptera) Western North American Naturalist 33(2) 91-108. PDF
     Abstract Fragment: "... The male, nymph, and egg of Pictetiella expansa (Banks) are described and an allotype female designated. ... Descriptions are either supported with original figures or reference is made to acceptable figures in the literature. Besides line drawings and halftones, useful photographic figures are provided which were prepared by using a scanning electron microscope."

Baumann,RW, Gaufin,AR and Surdick,RF 1977 The stoneflies (Plecoptera) of the Rocky Mountains. Memoirs of the American Entomological Society 31, 1-208. PDF
     Quote from page 133: "This species is uncommon but quite distinctive in adult and mature nymphal stages. The adults emerge from July through October."

Dodds,GS; Hisaw,FL 1925 Ecological studies on aquatic insects. IV. Altitudinal range and zonation of mayflies, stoneflies and caddisflies in the Colorado Rockies. Ecology 6(4), 380-390.
     Found nymphs above 3000m.

Kondratieff,BC and Baumann,RW 2002 A review of the stoneflies of Colorado with description of a new species of Capnia (Plecoptera: Capniidae). Transactions of the American Entomological Society 128 3, 385-401.
     Quote from page 397: " This species occurs in small to medium mountain streams. Most records are from high elevation streams in Gilpin, Grand and Larimer counties. Adults emerge from August to October but are rarely collected."

Maketon,M and Stewart,KW 1984 Drumming behavior in four North American Perlodidae (Plecoptera) species. Annals of the Entomological society of America, 77(5) 621-626.
     Abstract: " Drumming is described for the first time in three species of Perlodidae, Isoperla namata, Chernokrilus misnomus, and Pictetiella expansa. Signals of Isoperla signata are further described. Males of I. namata and I. signata produced monophasic calls of 10.0 ± 3.3 and 5.3 ± 1.0 beats, respectively, sometimes without stopping to a fixed position. Several pairs were tested, but females never answered male calls. C. misnomus and P. expansa exhibited two-way communication, with male/female signals overlapping in C. misnomus. Males of these two species called with modes of 9 and 13 beats, respectively. Male/female signal characteristics were species specific, when compared with those known for eight other species in the family. Age-related effects on drumming in C. misnomus and P. expansa are discussed. As in Perlidae, basic patterns of drumming and signal characteristics in the Perlodidae are highly diverse."

Stewart,KW 2004 Drumming Communication and Intersexual Searching Behavior of Stoneflies (Plecoptera). In Encyclopedia of Entomology (pp. 725-726). Springer Netherlands.
     Uses P. expansa as an example for comments on drumming.

Stewart,KW and Stark,BP 2002 Nymphs of North American Stonefly Genera. 2nd edition The Caddis Press, Columbus, Ohio. 510 pages. Photo of mature nymph pattern on page 111, figure 6.44

Verdone,CJ and Kondratieff,BC 2016 Description of the male terminalia of two western Nearctic Perlodinae (Pictetiella expansa (Banks) and Salmoperla sylvanica Baumann & Lauck). Illiesia 12(1):1-9.
     This paper has excellent photos and SEM images of P. expansa from the Front Range of Colorado.


Mesosternal Y-arms.
Only visible easily on mature nymphs.

"The only people with whom you should try to get even are those who have helped you. " - John E. Southard
Brown,WS 2004 Plecoptera or Stoneflies of Gunnison County, Colorado